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Alaifari, Rima (author), Bartolucci, F. (author), Steinerberger, Stefan (author), Wellershoff, Matthias (author)Gabor phase retrieval is the problem of reconstructing a signal from only the magnitudes of its Gabor transform. Previous findings suggest a possible link between unique solvability of the discrete problem (recovery from measurements on a lattice) and stability of the continuous problem (recovery from measurements on an open subset of R<sup>2...journal article 2024
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Van Mieghem, P.F.A. (author), Jokic, I. (author)Except for the empty graph, we show that the orthogonal matrix X of the adjacency matrix A determines that adjacency matrix completely, but not always uniquely. The proof relies on interesting properties of the Hadamard product Ξ = X ◦ X. As a consequence of the theory, we show that irregular co-eigenvector graphs exist only if the number of...journal article 2024
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Van Mieghem, P.F.A. (author)Although eigenvectors belong to the core of linear algebra, relatively few closed-form expressions exist, which we bundle and discuss here. A particular goal is their interpretation for graph-related matrices, such as the adjacency matrix of an undirected, possibly weighted graph.journal article 2024
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Corak, Nino (author)One possible way of proving the famous and important Riemann hypothesis would be to realize the Riemann zeta zeroes as the eigenvalues of some self-adjoint operator, using self-adjointness to show that the non-trivial zeroes all lie on the critical line. This is known as the Hilbert-Polya conjecture. Interpreting such a self-adjoint operator as...bachelor thesis 2023
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Meng, Zhaonan (author)This thesis aims to develop an advanced numerical solver capable of efficiently computing the resonant states of quantum mechanical two-body and three-body problems, thereby expanding our understanding of these complex systems. The quantum three-body problems feature at least two dimensions, which necessitates substantial computational efforts....master thesis 2023
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Zhong, BingXiang (author)Rank detection is crucial in array processing applications, as many algorithms rely on accurately estimating the rank of the data matrix to ensure optimal performance. Under Gaussian white noise, rank can be detected through eigenvalue analysis. However, in arbitrary noise, prewhitening the data matrix with the noise covariance matrix is...master thesis 2023
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Kluwer, Thomas (author)Global warming has caused an increasing demand for renewable energy. Currently, 50% of the renewable energy is provided by wind and solar combined. However, these renewable energy sources are highly volatile. Wave energy converters can provide a stable renewable energy source. Previous research has contributed to understanding various combined...master thesis 2023
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de Koster, P.B.J. (author), Wahls, S. (author)We present a fast method to calculate the significantly large solitonic components of signals with large time-bandwidth products governed by the nonlinear Schrödinger equation, for which the computation typically becomes prohibitively expensive and/or numerically unstable. We partition the full signal in both frequency and time to obtain...journal article 2023
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Jin, J. (author), Li, Z. (author)Empirical mode decomposition (EMD) lacks a strong theoretical support although extensively applied. We propose a theoretical framework for a succinct EMD in this work, with the assumption of invariant extrema locations for one IMF extraction. We define the envelope mean filter (EMF) and prove that the filter matrix satisfies five properties....journal article 2023
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Li, C. (author), Hendriks, R.C. (author)Spatial filtering techniques typically rely on estimates of the target relative transfer function (RTF). However, the target speech signal is typically corrupted by late reverberation and ambient noise, which complicates RTF estimation. Existing methods subtract the noise covariance matrix to obtain the target plus late reverberation covariance...conference paper 2023
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van Engen, Femke (author)Meditation is a contemplative practice that is believed to entail attentional and emotional regulation. One of the biggest challenges in developing personalized, accessible healthcare options with meditation is finding understandable features that signify whether someone is meditating. Specifically, there is no consensus on a feature resulting...master thesis 2022
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Ureña Baltierra, Gerardo (author)Mimetic formulations, also known as structure-preserving methods, are numerical schemes that preserve fundamental properties of the continuous differential operators at a discrete level. Additionally, they are well-known for satisfying constraints such as conservation of mass or momentum. <br/><br/>In the present work, a Mimetic Spectral Element...master thesis 2022
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Verlinde, Lander (author)This thesis uses the method of interlacing polynomials to study the behaviour of eigenvalues of a matrix after a rank-one update. Specifically, interlacing polynomials, common interlacing and interlacing families are exhaustively studied. These are excellent tools to find bounds on the eigenvalues of updated matrices by keeping track of how they...bachelor thesis 2022
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Yue, D. (author), Baldi, S. (author), Cao, Jinde (author), De Schutter, B.H.K. (author)This article addresses the continuous-time distributed optimization of a strictly convex summation-separable cost function with possibly nonconvex local functions over strongly connected digraphs. Distributed optimization methods in the literature require convexity of local functions, or balanced weights, or vanishing step sizes, or algebraic...journal article 2022
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Prins, Peter J. (author), Wahls, S. (author)We propose a numerical algorithm that computes the eigenvalues of the Korteweg–de Vries equation (KdV) from sampled input data with vanishing boundary conditions. It can be used as part of the Non-linear Fourier Transform (NFT) for the KdV equation. The algorithm that we propose makes use of Sturm-Liouville (SL) oscillation theory to guaranty...journal article 2022
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Dahlgren, F.S. (author), Gershkoff, Zachary (author), Hogben, Leslie (author), Motlaghian, Sara (author), Young, Derek (author)A hollow matrix described by a graph G is a real symmetric matrix having all diagonal entries equal to zero and with the off-diagonal entries governed by the adjacencies in G. For a given graph G, the determination of all possible spectra of matrices associated with G is the hollow inverse eigenvalue problem for G. Solutions to the hollow...journal article 2022
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He, Y. (author), Coutino, Mario (author), Isufi, E. (author), Leus, G.J.T. (author)In this work, we focus on partitioning dynamic graphs with two types of nodes (bi-colored), though not necessarily bipartite graphs. They commonly appear in communication network applications, e.g., one color being base stations, the other users, and the dynamic process being the varying connection status between base stations and moving...conference paper 2022
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Huang, N. (author), Ma, Yutao (author)We use tridiagonal models to study the limiting behavior of β-Laguerre and β-Jacobi ensembles, focusing on the limiting behavior of the extremal eigenvalues and the central limit theorem for the two ensembles. For the central limit theorem of β-Laguerre ensembles, we follow the idea in [1] while giving a modified version for the generalized...journal article 2022
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Hou, Jue (author), Liu, Zhou (author), Wang, Shaorong (author), Chen, Zhe (author), Xie, Wei (author), Fang, Cheng (author), Wei, Xinchi (author), Popov, M. (author)Supplementary control (SC) technology is widely leveraged by power supply companies in active distribution networks (ADNs) to improve their stability and dynamic characteristics. Yet, the existed SCs are generally implemented from inside the converter controllers of distributed generators (DGs) or active loads, so there is a need to redesign...journal article 2022
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He, Yanbin (author)Graphs can be models for many real-world systems, where nodes indicate the entities and edges indicate the pairwise connections in between. In various cases, it is important to detect informative subsets of nodes such that the nodes within the subsets are ’closer’ to each other. For example, in a cellular network, determining appropriate node...master thesis 2021